# ========= Copyright 2023-2024 @ CAMEL-AI.org. All Rights Reserved. =========
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ========= Copyright 2023-2024 @ CAMEL-AI.org. All Rights Reserved. =========

import io
import logging
import re
import tempfile
from pathlib import Path
from typing import List, Optional
from urllib.parse import urlparse

from PIL import Image

from camel.toolkits.base import BaseToolkit
from camel.toolkits.function_tool import FunctionTool
from camel.utils import dependencies_required

logger = logging.getLogger(__name__)


def _standardize_url(url: str) -> str:
    r"""Standardize the given URL."""
    # Special case for YouTube embed URLs
    if "youtube.com/embed/" in url:
        match = re.search(r"embed/([a-zA-Z0-9_-]+)", url)
        if match:
            return f"https://www.youtube.com/watch?v={match.group(1)}"
        else:
            raise ValueError(f"Invalid YouTube URL: {url}")

    return url


def _capture_screenshot(video_file: str, timestamp: float) -> Image.Image:
    r"""Capture a screenshot from a video file at a specific timestamp.

    Args:
        video_file (str): The path to the video file.
        timestamp (float): The time in seconds from which to capture the
          screenshot.

    Returns:
        Image.Image: The captured screenshot in the form of Image.Image.
    """
    import ffmpeg

    try:
        out, _ = (
            ffmpeg.input(video_file, ss=timestamp)
            .filter('scale', 320, -1)
            .output('pipe:', vframes=1, format='image2', vcodec='png')
            .run(capture_stdout=True, capture_stderr=True)
        )
    except ffmpeg.Error as e:
        raise RuntimeError(f"Failed to capture screenshot: {e.stderr}")

    return Image.open(io.BytesIO(out))


class VideoDownloaderToolkit(BaseToolkit):
    r"""A class for downloading videos and optionally splitting them into
    chunks.

    Args:
        download_directory (Optional[str], optional): The directory where the
            video will be downloaded to. If not provided, video will be stored
            in a temporary directory and will be cleaned up after use.
            (default: :obj:`None`)
        cookies_path (Optional[str], optional): The path to the cookies file
            for the video service in Netscape format. (default: :obj:`None`)
    """

    @dependencies_required("yt_dlp", "ffmpeg")
    def __init__(
        self,
        download_directory: Optional[str] = None,
        cookies_path: Optional[str] = None,
    ) -> None:
        self._cleanup = download_directory is None
        self._cookies_path = cookies_path

        self._download_directory = Path(
            download_directory or tempfile.mkdtemp()
        ).resolve()

        try:
            self._download_directory.mkdir(parents=True, exist_ok=True)
        except FileExistsError:
            raise ValueError(
                f"{self._download_directory} is not a valid directory."
            )
        except OSError as e:
            raise ValueError(
                f"Error creating directory {self._download_directory}: {e}"
            )

        logger.info(f"Video will be downloaded to {self._download_directory}")

    def __del__(self) -> None:
        r"""Deconstructor for the VideoDownloaderToolkit class.

        Cleans up the downloaded video if they are stored in a temporary
        directory.
        """
        import shutil

        if self._cleanup:
            shutil.rmtree(self._download_directory, ignore_errors=True)

    def download_video(self, url: str) -> str:
        r"""Download the video and optionally split it into chunks.

        yt-dlp will detect if the video is downloaded automatically so there
        is no need to check if the video exists.

        Returns:
            str: The path to the downloaded video file.
        """
        import yt_dlp

        video_template = self._download_directory / "%(title)s.%(ext)s"
        ydl_opts = {
            'format': 'bestvideo+bestaudio/best',
            'outtmpl': str(video_template),
            'force_generic_extractor': True,
            'cookiefile': self._cookies_path,
        }

        try:
            with yt_dlp.YoutubeDL(ydl_opts) as ydl:
                # Download the video and get the filename
                logger.info(f"Downloading video from {url}...")
                info = ydl.extract_info(url, download=True)
                return ydl.prepare_filename(info)
        except yt_dlp.utils.DownloadError as e:
            raise RuntimeError(f"Failed to download video from {url}: {e}")

    def get_video_bytes(
        self,
        video_path: str,
    ) -> bytes:
        r"""Download video by the URL, and return the content in bytes.

        Args:
            video_url (str): The URL of the video to download.

        Returns:
            bytes: The video file content in bytes.
        """
        parsed_url = urlparse(video_path)
        is_url = all([parsed_url.scheme, parsed_url.netloc])
        if is_url:
            video_path = self.download_video(video_path)
        video_file = video_path

        with open(video_file, 'rb') as f:
            video_bytes = f.read()

        return video_bytes

    def get_video_screenshots(
        self, video_path: str, amount: int
    ) -> List[Image.Image]:
        r"""Capture screenshots from the video at specified timestamps or by
        dividing the video into equal parts if an integer is provided.

        Args:
            video_url (str): The URL of the video to take screenshots.
            amount (int): the amount of evenly split screenshots to capture.

        Returns:
            List[Image.Image]: A list of screenshots as Image.Image.
        """
        import ffmpeg

        parsed_url = urlparse(video_path)
        is_url = all([parsed_url.scheme, parsed_url.netloc])
        if is_url:
            video_path = self.download_video(video_path)
        video_file = video_path

        # Get the video length
        try:
            probe = ffmpeg.probe(video_file)
            video_length = float(probe['format']['duration'])
        except ffmpeg.Error as e:
            raise RuntimeError(f"Failed to determine video length: {e.stderr}")

        interval = video_length / (amount + 1)
        timestamps = [i * interval for i in range(1, amount + 1)]

        images = [_capture_screenshot(video_file, ts) for ts in timestamps]

        return images

    def get_tools(self) -> List[FunctionTool]:
        r"""Returns a list of FunctionTool objects representing the
        functions in the toolkit.

        Returns:
            List[FunctionTool]: A list of FunctionTool objects representing
                the functions in the toolkit.
        """
        return [
            FunctionTool(self.download_video),
            FunctionTool(self.get_video_bytes),
            FunctionTool(self.get_video_screenshots),
        ]